Internal combustion engines utilize air and fuel such as gasoline, diesel fuel, alcohol, or alcohol-gasoline. This combination of fuel and air, often referred to as the “charge”, enters the combustion chamber and explodes as the piston compresses the charge and along with a spark created by a spark plug, except in traditional diesel engines in which the charge explodes as the diesel and air mixture is compressed. For optimum performance and consistent running of the engine, the combination of air and fuel must be controlled to create a charge that burns efficiently.
Various devices have been developed to control the amount of air and fuel in the charge. Most vehicles including passenger cars and motorcycles, utilize either a traditional carburetion or fuel injection to deliver fuel to the combustion chamber of an engine. Various forms of fuel injection have been developed such as single fuel injector, which sits above a throttle body, that intakes air, combines it with fuel and delivers the mixture to the cylinders. Fuel injectors may also be placed in the intake manifold to inject the fuel as the air travels through the intake and directs the mixture to the engine cylinders. Lastly, direct injection consists of one or more injectors that inject fuel directly into the combustion chamber or cylinder. These fuel injection systems typically utilize a computer, often referred to as the “ECU” (electronic control unit), along with sensors to measure the current operating conditions of the engine such as a manifold absolute pressure sensor, or “MAP” for short, to measure the pressure of air flowing through the intake manifold. The computer may also receive other operational conditions such as engine revolutions per minute, “RPM”, or charge temperature. The ECU receives the engine operating conditions and utilizes either algorithms or a look-up table to determine the optimal amount of fuel to inject for the air inspired to increase efficiency of the engine, referred to as stoichiometric ratio (14.7:1 for gasoline engines).
In performance applications such as racing, the driver or crew chief may attempt to control the delivery of fuel and air to the combustion chamber to find the optimum combination for a particular engine and racing application. All engines, including naturally aspirated engines (typically carbureted) and forced air engines (commonly referred to as “blown”), those that super or turbocharged, draw air from the atmosphere. Thus, the racer or crew chief must consider the current environmental conditions the vehicle will be operating in to formulate the most efficient or maximum power producing engine set-up.
Any change in temperature, barometric pressure, humidity or combination thereof will affect the performance characteristics of the engine due to the amount of oxygen available in the air. For example, on a day of low humidity, a standard volume of air will contain a certain percentage of oxygen, water vapor and other gas molecules. As the humidity increases, the amount of water vapor molecules increase and displace the molecules of oxygen and other gases resulting in the same standard volume of air with less oxygen for combustion and water vapor.
To increase the output of an engine (horsepower), many racers and high performance enthusiasts attempt to increase the density of the air the engine draws in. The drawn air is often called a “charge” and increasing the density of the charge means to increase the air molecules, oxygen molecules, in the standard volume of air. Increasing the density of the charge can be achieved by the addition of a turbo charger or a supercharger. The turbo charger uses the exhaust of the engine to turn a compressor that creates the density of the air before it enters the combustion chamber. One disadvantage of the turbo charger is that the exhaust also heats the air drawn into the engine system, which, in turn, partially reduces the density of the charge and thereby reduces the maximum horsepower added by the system. This is often seen in race cars and motorcycles that make more that one run or race in the same day such as in drag racing or in open wheel racing such as Indy car racing. Once the race vehicle has made a qualifying attempt, the crews will attempt to cool the engine by directing air over the engine with a large fan. In drag racing, it very common to see racers place bags of ice on the engine intake manifold or on the air filter canister which is in line with the intake manifold.
Albeit useful, the ice method is not often favored by the racers or the race officials. The melted ice often creates water puddles in the staging areas. Race officials and crews often check these puddles to ensure that the liquid is, in fact, water and not engine oil, transmission fluid or fuel. These liquids are a hazard in the staging areas and require prompt clean up or the wheels of the race vehicles may run through the liquids. Transmission and engine oils on race tires makes the tires slick and may cause them to spin and may cause the race vehicle to go out of control.
Some race engines use a compressor to increase the density of the charge entering the engine by actively drawing in air from the atmosphere and physically compressing it before it enters the combustion chamber. Turbo chargers use the exhaust from the engine to turn the compressor wheel which, in turn, compresses the intake air. The hot exhaust gases not only heat the driving compressor wheel, they also result in some heating the intake air manifold and the air traveling through it. Conversely, superchargers are driving mechanically by typically a drive belt. This assists in increasing the density of the charge because the exhaust does not heat the air entering the system. However, as the engine runs, the combustion process and the supercharger drive mechanism create heat that in turn, heats the components of the engine, including the air intake manifold. Thus, after a run or race, the racer or crew will also attempt to cool the engine and the air intake components by running air over the engine with a fan or by placing a bag of ice on the air intake manifold. As discussed above, this method also creates puddles of water creating the same concerns as stated.
Non-forced air engines, those without turbo or superchargers, also increase the temperature of the air entering the intake manifold by convention of the heat of the engine and friction created by the air molecules entering the intake system. Similarly, a race vehicle left in the sun will also absorb heat from the air and the sunlight. As the warm air heats the vehicle, the air intake manifold begins to warm, and also the gas tank and fuel lines heat up. Many racers and crew will attempt to shield the engine and fuel systems from the sun as the vehicle sits in the sun in the staging areas. Although this helps reduce the sunrays on the vehicle, these systems may still be warmed by the convention of the warm air.
In many forms of racing, strict rules are placed on the engine allowed in the race event. For example, the National Hot Rod Association (“NHRA”) limits the modifications on the race vehicles and engines. Thus, if a racer is having problems with the engine temperature and the racer may consider adding a larger volume cooling system. However, the racer must consult the rules to ensure that this modification is allowed. If the modification is not allowed, the racer will often attempt to assists the mandatory cooling system by using fans and ice on the engine in between passes or qualifying runs.
Moreover, many smaller race tracks do not have ice available for purchase at the race track and large tracks typically do not provide vending services during private test track sessions. Thus, the racer or crew must bring ice to the racetrack for use on the race vehicle. Over time, this ice may melt and can no longer be used on the intake manifold or air cleaner. It is not uncommon for the ice to melt by the end of the day.
A portion of the charge entering an engine is fuel. As the race vehicle sits in the sun, its fuel lines and fuel cell or tank also absorbs heat from the atmosphere and sunlight. It is well known in the art of high performance engines that actively cooling the fuel delivered to the engine will increase horsepower output. In drag and street racing the use of nitrous oxide is very common. Besides the fact that nitrous oxide is more combustible than air and fuel alone, the injection of high-pressure nitrous oxide into the air fuel mixture or charger also cools the charge, which increases the horsepower output of the engine. As such, may racers and crews attempt to keep the fuel cool before placing it in the fuel tank or cell. This may be actively done by placing the fuel delivery jug in an air-conditioned portion of the race trailer or tow vehicle or by placing the jug in a tub of water and ice.
Racers often try to cool other components of the race cars such as the fluid in automatic transmissions and the associated torque converters. In drag race applications, some race cars utilize a transmission brake to hold the car at a standing stop while allowing the race to increase the engine revolutions per minute (RPMs). This allows the race to quickly leave the starting line at the beginning of the race. A special solenoid is used to allow the fluid to engage first gear and reverse at the same time. When the solenoid is deactivated, the fluid is re-routed from reverse and car immediate moves in first gear. When the engine RPMs are high at the starting line with the transmission brake activated, the fluid in the transmission is turning the torque converter while the transmission is held. This fast spinning of the torque convert can create large amount of heat. If the racer were to engage the transmission brake and hold the engine at,high RPMs for a few minutes, the fluid temperate can rise over 400° F. and result in burning of the transmission fluid and even the paint on the torque converter. As the transmission fluid becomes hot, it also becomes more viscous or thinner. Thus, if the race car makes back to back runs, the hotter fluid may disengage the transmission brake quicker than when the fluid was cooler. This often results in inconsistent starting times and affects the over-all consistency of the race car. To overcome this inconsistency, racers will add transmission fluid coolers to the automatic transmission system. Likewise, the race may use a fan to blow air across the fluid cooler or transmission to cool the fluid or even place towels previously soaked in ice water around these components. These methods are often impractical in the staging lanes of a drag race and messy.
Therefore, it is desirable to have a cooling system that can be used to cool selective components of an engine or race vehicle after the vehicle has made a run or pass. Moreover, it is desirable to have a temporary cooling system what can be used while the race vehicle is sitting in the staging area of the racetrack without taking power away from the engine such as a 12 Volt fan or one that requires its own power source such as an electrical generator. Furthermore, it is desirable to have a cooling system which can be used as the engine is running that does not take away power from the engine such as fans, air or water pumps. A system for cooling the consumables of the engine that does not create a byproduct is also desired.